剂量分割法评价甘氨酸茶碱钠缓释片体内释放度及其体内外相关性

目的以剂量分割法分析甘氨酸茶碱钠缓释片(STG-ST,平喘药)的体内外释放相关性,并与Wagner-Nelson法进行比较。方法根据剂量分割法原理,计算STG-ST体内释放动力学;以Wagner-Nelson法,采用不同吸收速率常数计算STG-ST的体内吸收度。结果Wagner-Nelson法计算药物吸收度时,直接使用缓控释制剂的表观动力学参数,容易导致方法学错误;而剂量分割法得到的体内释放度与体外释放度相关性良好。结论无需注射剂作为参比,剂量分割法适合于缓释/控释制剂体内外相关性评价。

Application of the dose-division method in the in vivo release kinetics evaluation of the sodium theophylline glycinate sustained release dosage forms

Objective To evaluate the in vivo release behavior and its correlation with the in vitro release profile of sodium theophylline glycinate sustained release tablets (STG-ST) by the dose-division method in comparison with the correlation of absorption and release kinetics by Wagner-Nelson method.Methods The in vivo release profile of STG-ST was processed based upon the principles of the dose-division method, while the absorption profiles were processed by Wagner-Nelson method using two eliminate rate constants. Results The direct application of the Wagner-Nelson method to the controlled/sustained release systems might lead to methodological mistakes by using the apparent eliminate rate constant of the controlled/sustained release systems. The in vivo release profile by dose-division method was well correlated with the in vitro release kinetics of STG-ST. Conclusion The dose-division method is a novel and effective way for the in vitro-in vivo correlation-ship evaluation with no requirement of the injection parameters.